Garret Veloski

Measurement of atmospheric pollutants associated with oil and natural gas exploration and production activity in Pennsylvania’s Allegheny National Forest

Oil and natural gas exploration and production (E&P) activities generate emissions from diesel engines, compressor stations, condensate tanks, leaks and venting of natural gas, construction of well pads, and well access roads that can negatively impact air quality on both local and regional scales. A mobile, autonomous air quality monitoring laboratory was constructed to collect measurements of ambient concentrations of pollutants associated with oil and natural gas E&P activities. This air-monitoring laboratory was deployed to the Allegheny National Forest (ANF) in northwestern Pennsylvania for a campaign that resulted in the collection of approximately 7 months of data split between three monitoring locations between July 2010 and June 2011. The three monitoring locations were the Kane Experimental Forest (KEF) area in Elk County, which is downwind of the Sackett oilfield; the Bradford Ranger Station (BRS) in McKean County, which is downwind of a large area of historic oil and gas productivity; and the U.S. Forest Service Hearts Content campground (HC) in Warren County, which is in an area relatively unimpacted by oil and gas development and which therefore yielded background pollutant concentrations in the ANF. Concentrations of criteria pollutants ozone and NO2 did not vary significantly from site to site; averages were below National Ambient Air Quality Standards. Concentrations of volatile organic compounds (VOCs) associated with oil and natural gas (ethane, propane, butane, pentane) were highly correlated. Applying the conditional probability function (CPF) to the ethane data yielded most probable directions of the sources that were coincident with known location of existing wells and activity. Differences between the two impacted and one background site were difficult to discern, suggesting the that the monitoring laboratory was a great enough distance downwind of active areas to allow for sufficient dispersion with background air such that the localized plumes were not detected. Implications Monitoring of pollutants associated with oil and natural gas exploration and production activity at three sites within the Allegheny National Forest (ANF) showed only slight site-to-site differences even with one site far removed from these activities. However, the impact was evident not in detection of localized plumes but in regional elevated ethane concentrations, as ethane can be considered a tracer species for oil and natural gas activity. The data presented serve as baseline conditions for evaluation of impacts from future development of Marcellus or Utica shale gas reserves.

Monitoring, mitigation, and verification at sequestration sites: SEQURE technologies and the challenge for geophysical detection

Editors note: SEQURE is a trademark of The National Energy Technology Laboratory. A critical component of the National Energy Technology Laboratorys Sequestration Program is the development of tools that can reliably monitor and quantify the amount of CO2 that leaks to the surface. One major requirement for the commercial application of geologic sequestration is accurate leak detection; i.e., leak monitoring and accurate estimation of leak volumes through continued monitoring. This is essential to assure that long-term sequestration is achieved. Significant leakage from the sequestration reservoir defeats the purpose of sequestration, which is to stabilize and then reduce atmospheric concentrations of CO2 for several hundreds to thousands of years. Multiple investigators have attempted to estimate the amount of leakage that is acceptable (e.g., Pacala, 2002; Hepple and Benson, 2002; Dooley and Wise, 2002; Herzog, 2002). Their estimates vary considerably, and range from 1% to 0.01% per annum which leads to leakage of 50% of the injected CO2 volume in 70 to 7000 years, respectively.

Using Airborne Thermal Infrared Imagery And Helicopter EM Conductivity To Locate Mine Pools and Discharges In The Kettle Creek Watershed, North Central Pennsylvania

The Kettle Creek watershed contains 50–100-year-old surface and underground coal mines that are a continuing source of acid mine drainage (AMD). To characterize the mining-altered hydrology of this watershed, an airborne reconnaissance was conducted in 2002 using airborne thermal infrared imagery (TIR) and helicopter-mounted electromagnetic (HEM) surveys. TIR uses the temperature differential between surface water and groundwater to locate areas where groundwater emerges at the surface. TIR anomalies located in the survey included seeps and springs, as well as mine discharges. In a follow-up ground investigation, hand-held GPS units were used to locate 103 of the TIR anomalies. Of the sites investigated, 26 correlated with known mine discharges, whereas 27 were previously unknown. Seven known mine discharges previously obscured from TIR imagery were documented. HEM surveys were used to delineate the groundwater table and also to locate mine pools, mine discharges, and groundwater recharge zones. These sur...

Using helicopter electromagnetic "HEM… surveys to identify potential hazards at coal-waste impoundments: Examples from West Virginia

We have used 14 multifrequency helicopter-borne electromagnetic HEM surveys to determine the internal structure and integrity of mine-impoundment structures in West Virginia, U.S.A. — the first time such technology has been applied in this way and apparently well suited for such activities. The HEM surveys identified areas of concern in each of the impoundments investigated. In most cases, these were areas where filtrate was emerging high on the downstream embankment and represented an erosion risk. Of greater concern, the HEM survey identified thick bodies of slurry that remained unconsolidated and were buried deep beneath the embankment’s crest of some impoundments. Ground confirmation activities indicated that HEM survey interpretations provided an accurate representation of the conductivity distribution within coal-waste impoundments. We then interpreted the conductivity/depth images from the HEM surveys to provide a snapshot of hydrologic conditions that existed within the impoundment at the time of the survey. Resistivity profiles were obtained at the inactive impoundment along segments of flight lines from the HEM survey. HEM and resistivity surveys detected a conductive layer at a depth of about 7 m that was interpreted to be unconsolidated coal slurry. The methods also detected conductive bodies at a depth of about 26 m that were interpreted to be flooded mine works. Resistivity surveys from these segments corroborated HEM data, thereby providing independent confirmation of the HEM data and its processing. The resistivity and HEM surveys indicated a resistive surface layer where the coarse coal refuse was placed. Beneath the resistive surface layer is a conductive layer of unconsolidated or partially consolidated coal slurry. These highly loaded bodies of unconsolidated slurry are susceptible to solifluction, which can threaten embankment stability. Underground mine workings were identified in the HEM data from one impoundment.

Identification of Polycyclic Hydrocarbons in Fossilized Latex From Brown Coal

Abstract Partially coalified, structurally intact latex fibers(“Affenhaar”) found in a low-rank coal have been characterized by various analytical methods. It has been proposed in previous studies, and it appears to be so here, that the latex was “naturally” vulcanized during the coalification period. The Affenhaar samples studied here are high in sulfur. However, the sulfur constituents were not extracted in the pyridine solvent used to exact the hydrocarbons. Two fossilized latex samples recovered from different locations within the brown coal deposit were characterized. Pyridine extracts of the samples were analyzed by capillary gas chromatography, combined capillary gas chromatography-mass spectrometry, and high-resolution mass spectrometry. Twelve compounds in the extract were tentatively identified as amyrin and hopane biomarker derivatives by comparing the Kovats retention indices, mass spectra, and order of elution with those in the literature. Three of these, identifications were verified by coch...

Measurement of methane emissions from abandoned oil and gas wells in Hillman State Park, Pennsylvania

ABSTRACT Abandoned oil and gas wells, improperly plugged or unplugged, present a risk to current and future oil and gas development because they provide a potential pathway for unwanted gas and fluid migration to the surface. The appropriate emission factor for gaseous emissions from these wells is uncertain, as a limited number of studies have reported abandoned wells as a methane emissions source. A helicopter-based survey that mapped methane concentration and located wells by detecting magnetic anomalies was conducted in Hillman State Park in southwestern Pennsylvania. Although well finding via aerial survey was successful, elevated methane concentrations due to emissions from wells in the survey area were not detected by helicopter as abandoned wells were likely too small a source of methane to detect from elevations that helicopters fly at (tens of meters). Measurement of methane emission rates from 31 wells were collected using several techniques that are compared and evaluated for their effectiveness: Hi Flow sampler, field-portable flame ionization detector, infrared camera, dynamic flux chamber and bag sampling. Nine of the 31 wells were buried; average methane flux for these wells was not statistically different from the background. Mass flow rate from the remaining 22 wells ranged from non-detection (less than 0.09 kg CH4/day) to 4.18 kg CH4/day with a mean of 0.70 kg/well/day (median of 0.24 kg CH4/day/well) and a sample standard of error of 0.21 kg CH4/well/day. This emission factor, while not intended for exclusive use in developing a methane emissions inventory for abandoned oil and gas wells, contributes to the growing amount of methane emissions data for this source category. The results from the aerial survey, ground-based well location verification and emissions measurements, and the evaluation of measurement approaches described here, provide a comprehensive characterization of abandoned wells in one field that can inform future measurement studies.

Geophysics for Contaminant and Site Remediation

The water quality at the upstream and downstream of River Imeri was assessed with a view to determine the level of contamination of Cu, Pb, K, and Zn after observing that the river is contaminated with oil-sand. The results showed very strong correlations between the concentrations at the downstream and upstream. Cu with mean mass concentration of 0.083μgl-1was only detected at the downstream and Pb was not detected in the river. The mean mass concentrations of Zn at downstream and upstream were 0.573μgl-1 and 0.126μgl-1 respectively. The mean mass concentrations of K were 0.589μgl-1 and 0.345μgl-1 at downstream and upstream respectively which were comparable to the WHO limit values. The consumption of K either at upstream or downstream was lower than the reported value of 3700mg/day by WHO.

USING AIRBORNE ELECTROMAGNETIC SURVEYS TO IDENTIFY POTENTIAL HAZARDS AT COAL WASTE IMPOUNDMENTS: EXAMPLES FROM WEST VIRGINIA

Mine impoundments have in the past been a cause of catastrophic loss of life and destruction of property. To characterize this potential hazard, helicopter-mounted electromagnetic (HEM) surveys of coal waste impoundments were completed to identify fluid saturated zones within coal waste and to delineate the paths of filtrate fluid flow beneath the decant pond, through the embankment, and into adjacent strata or receiving streams. We also attempted to identify flooded mine workings underlying or spatially adjacent to the waste impoundment areas. In this effort, the National Energy Technology Laboratory of the United States Department of Energy (http://www.netl.doe.gov) conducted HEM surveys of 14 coal waste impoundments in southern West Virginia. Five electromagnetic frequencies were used in our surveys (385, 1700, 6536, 28120 and 116300 Hz) and processed using different inversion techniques to determine apparent conductivity depth images (CDI). Follow-up, ground-based resistivity surveys verified the results of the HEM survey. Overall, HEM and ground-based geophysical surveys proved to be effective in delineating the phreatic surface, determining seep locations, locating blockage in engineered drains, imaging areas of unconsolidated slurry, locating areas where process water has invaded adjacent aquifers, potentially depicting the possible location of flooded underground mine workings, locating infiltration zones into the abandoned mines and determining the spatial extent of impoundment impact.

THE USE OF AIRBORNE MAGNETIC AND EM CONDUCTIVITY SURVEYS TO LOCATE GROUNDWATER FLOW PATHS AT THE SULPHUR BANK MERCURY MINE SUPERFUND SITE 1

Airborne magnetic and electromagnetic (EM) conductivity surveys were conducted at the Sulphur Bank Mercury Mine Superfund Site near Clearlake, California to identify potential pathways for groundwater flow. The total field magnetic survey identified four fault zones that are potential conduits for mercury-contaminated, groundwater flow out of the flooded pit of the abandoned Sulphur Bank Mercury Mine. The location of the four fault zones was corroborated by the EM conductivity survey, which also provided evidence that the fault zones contained highly conductive water, either from deep, geothermal origin or from meteoric water made acidic by weathering of sulfide minerals and oxidation of H2S-bearing gases. This information was used to locate groundwater- monitoring wells and to provide assurance that all potential avenues for groundwater leaving the site were identified.

Introduction to Mass Spectrometric Techniques for Fossil Fuel Analysis

Mass spectrometry is a sensitive analytical technique that separates ions according to mass and measures the intensity of the signal derived from ions of each mass. The ions, or ion fragments are generated by bombarding molecules with electrons or other charged particles. A typical mass spectrum is a graphical or tabular report of the measured masses and their corresponding intensities usually normalized to the most intense specie (base peak) in the sample under investigation. Owing to the great sensitivity of most mass spectrometers, as little as a microgram of sample can afford a good spectrum.1